1. Field of the Invention
Recently, in order to obtain higher output of an engine, a plurality of intake ports are provided for each of the cylinders in the engine. For use in such an engine, an injector has been proposed having a plurality of guide holes through which fuel is guided into the respective intake ports.
The present invention relates to a multi-hole injector having a plurality of guide holes, and more specifically to a multi-hole injector with improved atomization and distribution.
2. Description of the Prior Art
An example of an injector having a plurality of guide holes is disclosed in U.S. Pat. No. 4,982,716. FIG. 5 shows the construction of the prior art injector. In FIG. 5, the injector includes a valve 126 for opening and closing a valve hole 118, and when the valve 126 is pulled upwardly, the valve hole 118 is opened and fuel Fp is injected from the valve hole 118. An adapter 145 is attached to a front end of the valve hole 118, and has a receiving hole 124 for receiving the injected fuel, the receiving hole 124 being divided downstream in a plurality of guide holes 137 through which the fuel is guided. The guide holes 137 are formed so as to be directed to corresponding intake ports (not shown). Assist air passages 138 are provided through side walls of the guide holes 137 so as to blow assist air into the guide holes 137.
In the injector thus constructed, fuel Fp injected from the valve hole 118 is introduced into the receiving hole 124 and then divided to be fed into the guide holes 137, where the fuel is atomized by assist air blown therein through the assist air passages 138 and is blown out toward the respective intake ports (not shown).
Another example of such a multi-hole injector is disclosed in U.S. Pat. No. 5,062,573. The construction of the injector is shown in FIGS. 6 and 7. The injector includes an adapter 145 formed with a receiving hole 124 which is divided downstream in three guide holes 137. The adapter 145 includes an atomization plate 130 disposed between the receiving hole 124 and the guide holes 137. As shown in FIG. 7, the atomization plate 130 includes an impactor 132 against which fuel injected from the valve hole 118 impacts to be atomized and three openings 136 through which the atomized fuel is introduced into the guide holes 137.
In the injector as disclosed in either of the above mentioned U.S. Pat. Nos. 4,982,716 and 5,062,573, the fuel injected from the valve hole 118 is received in the receiving hole 124 and then divided to be introduced into the guide holes 137. If there is any deviation in the positional relationship between the valve hole 118 and the guide holes 137, a larger amount of fuel will flow into one of the guide holes 137, while a smaller amount of fuel will flow into another one. This causes difficulty in achieving good distribution of fuel.